The New England

Journal of Medicine © Co py r ight , 2 0 0 1 , by t he Ma s s ac h u s e t t s Me d ic a l S o c iet y

FEBRUARY 8, 2001

VOLUME 344

NUMBER 6

LONGITUDINAL ASSESSMENT OF NEUROCOGNITIVE FUNCTION AFTER CORONARY-ARTERY BYPASS SURGERY MARK F. NEWMAN, M.D., JERRY L. KIRCHNER, B.S., BARBARA PHILLIPS-BUTE, PH.D., VINCENT GAVER, B.S., HILARY GROCOTT, M.D., ROBERT H. JONES, M.D., DANIEL B. MARK, M.D., JOSEPH G. REVES, M.D., AND JAMES A. BLUMENTHAL, PH.D., FOR THE NEUROLOGICAL OUTCOME RESEARCH GROUP AND THE CARDIOTHORACIC ANESTHESIOLOGY RESEARCH ENDEAVORS INVESTIGATORS*

ABSTRACT Background Cognitive decline complicates early recovery after coronary-artery bypass grafting (CABG) and may be evident in as many as three quarters of patients at the time of discharge from the hospital and a third of patients after six months. We sought to determine the course of cognitive change during the five years after CABG and the effect of perioperative decline on long-term cognitive function. Methods In 261 patients who underwent CABG, neurocognitive tests were performed preoperatively (at base line), before discharge, and six weeks, six months, and five years after CABG surgery. Decline in postoperative function was defined as a drop of 1 SD or more in the scores on tests of any one of four domains of cognitive function. (A reduction of 1 SD represents a decline in function of approximately 20 percent.) Overall neurocognitive status was assessed with a composite cognitive index score representing the sum of the scores for the individual domains. Factors predicting long-term cognitive decline were determined by multivariable logistic and linear regression. Results Among the patients studied, the incidence of cognitive decline was 53 percent at discharge, 36 percent at six weeks, 24 percent at six months, and 42 percent at five years. We investigated predictors of cognitive decline at five years and found that cognitive function at discharge was a significant predictor of long-term function (P